Injection locking of a diode laser is essential in a majority of fields, such as laser spectroscopy [1]}, [2]}, laser cooling and trapping [3]}, [4]}, [5]}, [6]}, [7]}, [8]}, optical communication [9]}, [10]}, [11]} and high-precision metrology [12]}, [13]}, [14]}, [15]}. It allows phase and frequency locking of a "slave" laser in reference to a "master" laser by an optical link [16]}. Among the advantages of using injection locking of the diode are its cost-effectiveness, flexibility and efficiency. For example, it offers a simple solution to provide a clean laser source without a special design of laser diodes or controllers. The spectral mode of injection locked slave laser is nearly dependent on the master laser. Most of single mode diode lasers, including some multimode diode lasers can be used for injection locking. This feature allows us to harness injection locking for achieving a relatively high power single-frequency diode laser source, without using an optical grating that causes significant optical loss. Beside those advantages, the injection locking scheme can also be exploited as active optical filters in quantum optics [17]}.
